One of the applications of the present invention relates to silos for mass-produced bottles of plastic, or to factories for filling bottles with mineral water or with other drinks.
In the field relating to human food consumption, the greatest precautions with respect to cleanliness and hygiene are required.
In such manufacturing facilities, the plastic bottles, for example, made of polyvinyl chloride, or PVC, are manufactured, to the extent of the amount present in the bottling chain, by a first chain of extruders for quickly mass-producing the containers of plastic material, particularly of PVC, and by an extrusion/blowing process, whereby the containers are able to hold the mineral water distributed in this manner to the consumers.
In view of the high speed of production of these bottles at a high rate, which, however, is frequently interrupted by restocking, it is desirable to provide a restocking stack in several silos.
Inasmuch as this process relates to the field of food, maintenance of the greatest degree of hygienic cleanliness, and a minimum presence of any bacteria is absolutely essential.
Furthermore, for such contents of little commercial value, and reduced process-dwelling time, only silos of great capacity have been shown to be economically desirable.
Additionally, as these products are stocked for only a short time following their manufacture, and as the material used in such bottles is somewhat exposed to the atmosphere, there arises a need for natural or artificial ventilation for discharging such products, primarily chlorified products.
This phase is conventionally called dechlorinization.
In the event of any incorrect or incomplete discharge of these products, the latter remain in the bottles, even in residual amounts, and are passed on their subsequent contents after refilling, leaving a taste which is not very pleasant, and not appreciated by consumers.
For this purpose there already exist aerated silos, formed by a metallic base inclined towards a discharge port, and formed with lateral and upper grilled surfaces in the framework.
Even if the ventilation proceeds quite adequately, at least in the upper part, for complete dechlorinization, in view of access difficulties, neither the conditions required within the processing time, nor those for perfect cleanliness are met.
Furthermore, the shape of the bottles having a square or rectangular cross-section, and disposed in bulk in the silo, as well as the low weight of the bottles, do not aid their discharge movement along an inclined discharge plane.
The attending personnel is obliged to push, or to aid certain bottles descending along the inclined plane, and along the fluid discharge channel by means of repeated pushes on the rear face of the thin plates, and this also applies to any jammed bottles.
Such pushes, which are sometimes violent, cause the base of the silo to deteriorate at a evel of separation of the plates, and deform the latter by impacts in such a manner that they no longer constitute a sufficiently plane sliding surface.
So as to facilitate the use of cleaning and disinfecting agents or equipment, the base of the aforenoted that type of silo is implemented in the form of fixed and removable panels, which can be conveniently removed and displaced, so as to ensure adequate cleaning, and subsequent re-mounting.
In order, however, to avoid such interventions, an automatic interior cleaning system can be provided, for example in the form of turnstiles or of swiveled balls, or any other cleaning assembly operable by fluid pressure, which fulfills the same conditions, and operates in a similar manner.
This assumes silos which are perfectly and tightly sealable, and have a smooth internal surface free of any projections, or other irregularities or material defects.
Furthermore, in order to ensure the required mechanical rigidity, the necessarily large dimensions of such silos lead to the employment of thick, and consequently heavy and expensive plates, which are difficult to emplace.